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MAXI J1820+070 is a low-mass X-ray binary with a black hole (BH) as a compact object. This binary underwent an exceptionally bright X-ray outburst from 2018 March to October, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 h of observations of the MAXI J1820+070 outburst with the H.E.S.S. MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi -LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy (HE) gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi -LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to ∼500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential HE and very-HE gamma-ray emitting region should be located at a distance from the BH ranging between 1011 and 1013 cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA. [ABSTRACT FROM AUTHOR]

This work presents the results of experimental and theoretical studies of the magnetic properties of the LiYb F 4 single crystal and powder samples, and magnetoelastic properties of the LiYb F 4 single crystal samples, at low temperature and applied field range of 0-9 T. The magnetostriction experimental data for the single crystal of LiYb F 4 is published for the first time. The magnetization and magnetostriction were calculated in the framework of the exchange-charge model taking into account dipole–dipole and electron-deformation interactions, with the calculation of the electron-deformation parameters. The theoretical analysis presents quantitative agreement in the temperature range of 2–10 K with the magnetization and magnetostriction measurements of the LiYb F 4 samples. • Experimental magnetostriction data shows high anisotropy of the magnetoelastic properties. • Exchange-charge model describes magnetic properties of LiYb F 4 crystals at 2 < T < 300 K. • Magnetic properties of LiYb F 4 single crystal have four-fold symmetry. • Set of electron-deformation parameters for LiYb F 4 was calculated. [ABSTRACT FROM AUTHOR]

We study current-perpendicular-to-plane (CPP) geometrical giant magnetoresistance (GMR) and magnetic switching property for single spin-valves (SVs). Applying a synthetic antiferromagnet (SyAF) instead of a single ferromagnet film as a free layer, the resistance-change area product ΔRA of the SVs is strongly enhanced from ∼ 1.84 mΩ μm² to ∼ 16.8 mΩ μm² and the CPP-GMR ratio changes from 0.8% to 3.6%. The study of the magnetic switching behavior by both experiment and single-domain thermal activation modeling shows that the SVs with SyAF as a free layer approaches a single-domain magnet even with a low aspect ratio 1 as long as its size diminishes to ∼0.18 μm². Because of the single-domain structure, the SVs with SyAF give a size-independent magnetic switching field when the aspect ratio is 1. [ABSTRACT FROM AUTHOR]

A magnetic sensor which consists of a compound magnetic wire and search coil has a novel performance to induce the detection voltage independent of changing rate of AC external field frequency in every one cycle. The detection voltage is changed by the previous magnetized state of the compound magnetic wire. This paper reports the effect of a DC bias magnetic field which is applied with an AC magnetic field to make an asymmetric field. To make a compound wire a previous magnetized state, the demagnetized wire is magnetized by various orienting DC field H/sub 0/. When a symmetric AC field Hex and DC bias field Hb are applied to the wire, the wire is magnetized by an asymmetric magnetic field, which consists of a reset field Hr=Hex+Hb and a set field Hs=Hex-Hb. According to the relationship among the critical field Hp, H/sub 0/ and Hb, Hp is independent of the previous magnetized state of wire at Hb of 25 Oe or larger, and the pulse voltage is always induced at a fixed Hp. This phenomenon is very stable and reproducible. [ABSTRACT FROM PUBLISHER]

Abstract: Anisotropic magnetic properties of the cubic intermetallic compounds RCu4Ag(R=Gd–Er) single crystals are studied in the temperature range between 4.2 and 300K and in magnetic field up to 50kOe. The magnetization with Gd and Tb are found to order antiferromagnetically and with Dy, Ho and Er exhibit ferromagnetic behavior. It was found that the magnetic easy axes of ferromagnetic compounds DyCu4Ag, HoCu4Ag and ErCu4Ag are the [100], [110] and [111] directions, respectively. [Copyright &y& Elsevier]